Geologists Say Rivers Will Change Course With Flooding

(Host) Nearly every river in
southern Vermont adjusted course or experienced severe erosion in the
flooding caused by Tropical Storm Irene.

VPR's Jane Lindholm explains
that much of the destruction was caused by Vermont's geology, coupled with a couple hundred years of
human intervention.

(Lindholm) To understand why Vermont's rivers flooded the way they did last week means stepping
back to when our modern landscape was formed.

(Becker) The major river courses-valley courses, let's
put it that way, were carved long ago, even before the glaciers.

(Lindholm) State Geologist
Larry Becker says the glaciers deposited new materials on our valley
floors. Rivers carved these glacial
deposits into riverbeds and formed floodplains to spill into during major
rainstorms.

During the industrial
revolution, we harnessed the power of
the rivers for energy and commerce, populated the surrounding floodplains with
homes and businesses, and built roads alongside riverbeds to move people and
products from one place to another. And
we straightened and diverted rivers when their paths were too meandering for
our liking.

Mike Kline is the River
Management Director for the state of Vermont.

(Kline) "Many activities that went on for over a
couple hundred years involved moving the river slowly but surely out of the way
of our human activities in these valleys."

(Kline) "Well now here what we've seen is, in 48
hours, many of these stream channels have gone all the way through the
evolutionary process, completely eroding both banks, recreating this huge
depositional feature that will one day turn into a new floodplain for these
systems. And it just happened overnight."

(Lindholm) Overnight and over
roads, bridges, and into people's homes.
In some towns, residents who say they couldn't even see the local river before Irene, now find it flows through their
backyards.

What does this mean for
landowners?

(Donegan) Well, from an insurance point of view it's
an interesting question because there's not much your insurance is going to do
to help you recover from that."

(Lindholm) Susan Donegan is Deputy
Secretary of BISHCA, the state department that regulates insurance. Donegan says figuring out property rights is
going to be a tricky legal issue.

(Donegan) "Those are going to be questions that are
going to have to be legally answered through a look at what's called riparian
rights. Lawyers are going to have to
probably get into the picture. And
perhaps even towns are going to have to have an understanding of what happens
when these types of streams and properties move."

(Lindholm) River Management
Director Mike Kline says past flooding records show that in some cases property
lines moved with the river boundaries.
But in cases where the river took a whole new course, the property lines
sometimes stay in place. But, Kline
says, it's unclear what will happen in this case.

(Kline) This would be a really good time to get folks
in the legal profession to look at this issue carefully because this question
needs to be answered very succinctly for people."

(Lindholm) Many questions
remain. Should we rebuild homes and
businesses-not to mention the state office complex in Waterbury-that lie, or now lie, in floodplains? Should the rivers be manipulated so that they
don't flow where our state highways are being rebuilt? Kline says those discussions are already
underway in the Agency of Natural Resources and the Agency of Transportation. But we will have to get better at sharing our
landscape with what we all now understand are very dynamic rivers.